I have the following problem.
GT 1.916v jtd.
During driving sometimes there is no reaction on the accelerator pedal.
Even full pressed motor goes to idle. After pressing clutch and pumping with the accellerator pedal the motor start to react as normal and all is OK again.

This occurs 2 times a day.....hot cold all the same.

Example: I drive a highway 130km/h for a while, in one moment the motor reacts like I let go of the pedal. But it is still in the same position. I have to do like above play with the accelerator pedal and clutch and all is normal again. No light's alarms no errors stored.

Just a guess - what if the brake switch signal to the engine management is intermittently sticking on activating a cross-check that stops you accelerating at the same time as braking? Pressing the clutch enables the accelerator again as it thinks you're not fighting the brakes any more. No idea if this cross-check actually exists on Alfas although Toyota certainly wish they'd had it!

I'd check the plug connector onto the throttle pedal assembly, and the wiring from it - its possible that somehow the cabling is getting caught or pulled when the clutch pedal is pressed, causing some stress on the connector?.

I've seen that once, when a lightbulb was about to die.... the lightbulb turned purple, the engine didn't respond and neither did the idle get regulated. if you added load on the engine the rpm dropped to well below 500...